Phil Hughes
--- a/app/assets/javascripts/labels_select.js
+++ b/app/assets/javascripts/labels_select.js
            }
            $value.removeAttr('style').html(template);
            $sidebarCollapsedValue.text(labelCount);
+
+            if (data.labels.length) {
+              labelTooltipTitle = _.chain(data.labels)
--- a/CHANGELOG
+++ b/CHANGELOG
  - Reduce size of HTML used by diff comment forms
  - Protected branches have a "Developers can Merge" setting. !4892 (original implementation by Mathias Vestergaard)
  - Fix user creation with stronger minimum password requirements. !4054 (nathan-pmt)
+  - Added tooltip listing label names to the labels value in the collapsed issuable sidebar
+  - Fix user creation with stronger minimum password requirements !4054 (nathan-pmt)
--- a/spec/features/issues/issue_sidebar_spec.rb
+++ b/spec/features/issues/issue_sidebar_spec.rb
+
+      it 'should update the tooltip for collapsed sidebar' do
+        page.within('.block.labels') do
+          find('.edit-link').click
+
+          page.within('.dropdown-menu-labels') do
+            click_link 'a'
+            click_link 'b'
+            click_link 'c'
+            click_link 'd'
+            click_link 'e'
+            click_link 'f'
+          end
+
+          find('.edit-link').click
+          sleep 1
--- a/app/helpers/issuables_helper.rb
+++ b/app/helpers/issuables_helper.rb
    end
  end

+  def issuable_labels_tooltip(labels)
+    max_labels = 5
+    label_size = labels.size
+    label_names = labels.each_with_index.map do |label, i|
--- a/spec/features/issues/issue_sidebar_spec.rb
+++ b/spec/features/issues/issue_sidebar_spec.rb
    end
  end

+  context 'update labels', js: true do
--- a/spec/features/issues/issue_sidebar_spec.rb
+++ b/spec/features/issues/issue_sidebar_spec.rb
+    before do
+      project.team << [user, :developer]
+      visit_issue(project, issue)
+    end
+
+    context 'more than 5' do
+      before do
+        create(:label, project: project, title: 'a')
+        create(:label, project: project, title: 'b')
+        create(:label, project: project, title: 'c')
+        create(:label, project: project, title: 'd')
+        create(:label, project: project, title: 'e')
+        create(:label, project: project, title: 'f')
+      end
+
+      it 'should update the tooltip for collapsed sidebar' do
--- a/app/helpers/issuables_helper.rb
+++ b/app/helpers/issuables_helper.rb
    end
  end

+  def issuable_labels_tooltip(labels, limit: 5)
+    first, last = labels.partition.with_index{ |_, i| i < limit  }
--- a/CHANGELOG
+++ b/CHANGELOG
  - API: Endpoints for enabling and disabling deploy keys
  - API: List access requests, request access, approve, and deny access requests to a project or a group. !4833
  - Use long options for curl examples in documentation !5703 (winniehell)
+	- Added tooltip listing label names to the labels value in the collapsed issuable sidebar
--- a/spec/helpers/issuable_helper_spec.rb 0 → 100644
+++ b/spec/helpers/issuable_helper_spec.rb 0 → 100644
+require 'spec_helper'
+
+describe IssuablesHelper do 
--- a/spec/javascripts/fixtures/issue_sidebar_label.html.haml 0 → 100644
+++ b/spec/javascripts/fixtures/issue_sidebar_label.html.haml 0 → 100644
+.block.labels
+  .sidebar-collapsed-icon.js-sidebar-labels-tooltip
+  .title.hide-collapsed
+    %a.edit-link.pull-right{ href: "#" }
+      Edit
+  .selectbox.hide-collapsed{ style: "display: none;" }
+    .dropdown
+      %button.dropdown-menu-toggle.js-label-select.js-multiselect{"data-ability-name" => "issue", "data-field-name" => "issue[label_names][]", "data-issue-update" => "/root/test/issues/2.json", "data-labels" => "/root/test/labels.json", "data-project-id" => "12", "data-show-any" => "true", "data-show-no" => "true", "data-toggle" => "dropdown", :type => "button"}